Note: Descriptions are shown in the official language in which they were submitted.
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FASTENER SYSTEM INCLUDING A CLAMP-FORCE INDICATING INSERT
Field of the Invention
The present invention relates to a fastener system which includes a clamp-
force
indicating insert.
Background of the Invention
. Inserts for providing an indication of a clamp-force exerted by a nut
threaded
on a bolt are known in the art. These inserts function to indicate that an
appropriate
clamp force has been achieved by the tightening of the nut on the bolt.
However,
upon loosening of the nut, these inserts are not rotationally coupled to the
nut.
Therefore, when the nut is loosened, the insert often becomes disengaged from
the
nut. The insert must then be inconveniently, separately screwed off the bolt
or cut
off. Additionally, separation of the compressed insert from the nut allows the
loosened nut to spin freely off, increasing the likelihood of separation of
the
previously fastened components.
It would be desirable to have a nut which includes a clamp-force indicating
insert which is rotationally coupled to the nut when the nut is loosened,
thereby
avoiding the inconveniences mentioned above. It would also be desirable to
have a
nut that would not spin freely off the fastener threads even after separation
of the
insert.
Summary of the Invention
In accordance with one aspect of the present invention, there is provided a
fastener system which includes a nut having a body. The body has a top face
and
a bottom face. The body further has an orifice extending therethrough. The
system
also includes a clamp-force indicating insert for use with the nut. The insert
includes
a deformable portion extrudable across the top face of the nut. The nut
further
includes at least one insert-engaging portion. The insert-engaging portions
can be,
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for example; a protrusion, an indentation, a circumferential groove, or an
adhesive,
or the like. Additionally, since asymmetrical overall shape can accomplish the
same
rotational coupling as that which results from the addition of complementary
indentations/projections to the perimeter of an otherwise circular design,
insert
engagement can be accomplished through any asymmetrical complementary shaping
of the insert and corresponding nut orifice, sufficient to accomplish
rotational
coupling.
In one embodiment of the present invention, the top face of the nut further
includes a recess disposed about the orifice and the clamp-force indicating
insert
further includes a portion for insertion into the recess.
In another embodiment of the present invention, the body of the nut includes
a second orifice, through which a pin can be inserted.
In accordance with another aspect of the present invention, there is provided
a fastener system which includes a nut having a body. The body has a top face
and
a bottom face. The body further has an orifice extending therethrough. The
system
also includes a clamp-force indicating insert for use with the nut. The insert
includes
a portion extrudable across the top face of the nut. The insert further
includes at
least one nut-engaging portion.
In accordance with yet another aspect of the present invention, there is
provided a fastener system which includes a nut having a body. The body has a
top
face and a bottom face. The body further has an orifice extending
therethrough.
Rotation of the nut on a bolt extending through the orifice provides for the
exertion
of a clamp force by the nut against a surface. The fastener system also
includes
means for indicating the clamp force applied by the nut on the surface. The
means
for indicating the clamp force is disposed between the top face of the nut and
the
surface. The fastener system also includes means for rotationally coupling the
nut
and the clamp-force indicating means.
In accordance with still another aspect of the present invention there is
provided
a clamp-force indicating insert for use with a nut. The insert includes a
portion for
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insertion into the recess of the nut. The insert also includes a portion for
providing
an indication of a clamp force and a nut-engaging portion.
In accordance with a further aspect of the present invention there is provided
a nut for use with a clamp-force indicating insert, the nut having a body, the
body
having a top face and a bottom face, the body further having an orifice
extending
therethrough. The top face further includes an insert-engaging portion for
rotationally
coupling a clamp-force indicating insert to the nut. The insert engaging
portion is
selected from the group consisting of a recess disposed in the top face, the
recess
having an at least partially asymmetrical perimeter; a recess disposed in the
top face,
and a slot formed at least partially about the recess; or an orifice disposed
through
the at least one side face of the nut.
Other features and advantages of the invention will become apparent from the
following detailed description, taken in conjunction with the accompanying
drawings
which illustrate, by way of example, various features of preferred embodiments
of the
invention.
Description of the Figures
The detailed description of the invention will be made with reference to the
accompanying drawings, where like numerals designate corresponding parts of
the .
figures. The drawings are meant to be generally illustrative of various
examples of
the present invention, but are merely examples and are not meant to be
limiting of
the scope of the invention.
FIG. 1 is a top perspective view of a nut of the present invention.
FIG. 2 is top perspective view of a clamp-force indicating insert of the
present
invention.
FIG. 3 is a top perspective view of another embodiment of a nut of the present
invention.
FIG. 4 is a top perspective view of another embodiment of a nut of the present
invention.
FIG. 5 is a top view of another embodiment of a nut of the present invention.
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FIG. 6 is a top view of another embodiment of a clamp-force indicating insert
of the
present invention.
FIG. 7 is a top view of another embodiment of a nut of the present invention.
FIG. 8 is a top view of another embodiment of a clamp-force indicating insert
of the
present invention
FIG. 9 is a top view of another embodiment of a nut of the present invention.
FIG. 10 is a cross-sectional view through line 10-10 of FIG. 9.
FIG. 11 is a cross-sectional view of another embodiment of a nut of the
present
invention.
FIG. 12 is a cross-sectional view of another embodiment of a clamp-force
indicating
insert of the present invention.
FIG. 13 is a top perspective view of another embodiment of a nut of the
present
invention.
FIG. 14 is a top perspective view of another embodiment of a clamp-force
indicating
insert of the present invention.
Detailed Description of the Invention
As depicted in FIGS. 1-2, nut 10 includes a sidewall 11, a top face 12 and a
bottom
face 13. The top face is the clamping face, i. e., the face which is tightened
against a surface
through which a bolt has been extended. In a preferred embodiment, top face 12
includes a
recess 19. The recess 19 includes a bottom wall 17 and a sidewall 18. Nut 10
also includes
an orifice 14 therethrough. The orifice 14 is preferably threaded. Top face 12
includes
insert-engaging portions 15a, 15b and 16. In this particular embodiment,
insert-engaging
portions 15a, 15b and 16 comprise indentations, such as slots. Slots 15a and
15b are
preferably substantially perpendicular to a line tangent to orifice 14 at
slots 15a or 15b. Slot
16 preferably forms an a non-perpendicular angle to a line tangent to orifice
14 at slot 16.
Either type of slot can be used in combination with additional slots of the
same type or in
combination with at least one additional slot of the other type. It is to be
understood
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that only a single insert-engaging portion is necessary. However, one or more
additional insert-engaging portions can be beneficially provided.
Preferably, insert 20 includes a portion 22 extrudable across top face 12 of
nut
10, and a portion 21 for insertion into recess 19. By extrudable, it is meant
that this
portion is squeezable in that under stress this portion compresses and
stretches.
Portion 21 includes opposed edges 23 and 24. If recess 19 is cylindrical then
portion
21 is preferably cylindrical around its outer surface. Cylindrical portion 21
has a
height and a diameter which allow it to be fitted within recess 19. Once
cylindrical
portion 21 is fitted within recess 19, portion 22 is disposed above top face
12. See
FIG. 11. In a preferred embodiment, portion 22 is a deformable/extrudable lip.
However, other embodiments are possible. For example, portion 22 can initially
extend above portion 21 as a cylindrical tube. Upon the tightening of the nut
against
a surface, the surface will exert a force on portion 22 causing it to be
extruded
between top face 12 and the surface. In those embodiments in which nut 10 does
not include recess 19, the insert can include tabs for engaging at least one
sidewall
and preferably two opposed sidewalls of nut 10. As depicted in Fig. 14 this
type of
insert, insert 150 has tabs 152a and 152b which are disposed about the outer
edge
of insert.150 for engaging two opposed sidewalls of the nut. Other
arrangements
and numbers of tabs can be used. For example, a continuous tab which engages
the
entire outer perimeter of the nut. Alternatively, insert 20 can be placed on a
bolt to
which nut 10 is to be threaded.
With insert 20 in place in nut 10, nut 10 can be affixed to a bolt (not shown)
which has been inserted through at least one surface. The surface or surfaces
can
be any portion of any device, devices, materials and the like which are to be
fastened
by a nut and a bolt as is standard in the fastening art. Upon tightening of
nut 10 on
the bolt, top face 12 of nut 10 will rotate towards the surface through which
the bolt
extends. Portion 22 is interposed between this surface and top face 12. As nut
10
is tightened, portion 22 is compressed between this surface and nut top face
12.
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This tightening of nut 10 has two effects. One effect is that a part of
portion
22 is forced into slots 15 and 16. A second effect is that upon continued
tightening
of nut 10, a part of portion 22 is compressed to an extent which indicates
that an
appropriate clamp force is being exerted by nut 10. In a particular
embodiment, the
compression of portion 22 can include the complete severance of an outer part
of lip
22 from an inner part of lip 22. This result occurs because insert 20 is
formed of
compressible, extrudable material, preferably plastic, and nut 10 is formed of
substantially non-compressible, non-deformable material, preferably metal.
Once it is no longer desired that nut 10 apply a clamp force to the surface
through which the bolt extends, nut 10 can be loosened and removed from the
bolt.
If a prior art clamp-force insert had been used, upon loosening, frequently
the clamp
force insert would separate from the nut. The insert then had to be either
inconveniently, separately rotated off or inconveniently cut off. However, the
present
invention prevents the separation of the insert and the nut, through the
engagement
of any one or all of slots 15a, 15b and 16 with a part of portion 22. The
engagement
between any one of slots 15a, 15b and 16 and a part of portion 22 provides for
a
rotational coupling of the nut and the insert, thereby preventing or at least
greatly
reducing the incidence of insert and nut separation. It is to be understood
that in this
embodiment of the invention, insert 20 initially need not and preferably does
not
include portions which engage nut 10 prior to the application of a clamping
force to
insert 20. The application of the clamping force deforms the insert and forces
a
portion of it into engaging portions on the nut and thereby rotationally
couples the
nut and the insert. As described in more detail below, in alternative
embodiments,
insert 20 includes preformed portions which engage complementary portions
shaped
in the nut prior to an application of a clamping force.
Insert 20 is formed of a compressible material, particularly an extrudable
material, and most particularly a severable material that will sever under
desired
clamp forces. Insert material and thickness can be varied as a means of
directing
installation to a particular clamp force that is desired. Other means of
indicating a
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clamping force are within the scope of the present invention. For example,
materials
which can change color upon application of a force thereto or provide any
other
human sensible signal upon application of a clamping force. Preferred
materials
include extrudable plastics and rubber. One specific plastic material of
utility is DOW
HDPE #25455N.
The insert and the nut can be provided together. If the insert and nut are
provided together, in the same package; for example, the insert and nut can be
provided already coupled together or uncoupled. The insert and nut can also be
provided separately, for example, in different packages for eventual coupling
by an
end user. The nut may be used multiple times. In general, a new insert is
required for
each installation.
FIGS. 3 and 4 disclose alternative embodiments of nut insert-engaging
portions.
Nut 40 includes a sidewall 42, a top face 41 and a bottom face 48. Top face 41
includes a recess 46. The recess 46 includes a bottom wall 44 and a sidewall
45.
Nut 40 also includes an orifice 43 therethrough. The orifice 43 is preferably
threaded. Bottom wall 44 also includes at least one protrusion 47. As
described
above an insert can be placed in recess 46 and nut 40 tightened. Upon
tightening,
protrusion 47 will imbed a portion of cylindrical portion 21 of insert 22,
(FIG. 21. This
engagement of insert 22 and nut 40 provides for a rotational coupling of the
nut and
the insert, thereby preventing or at least greatly reducing the incidence of
insert and
nut separation. In alternative embodiments, in place of protrusion 47 at least
one
indentation can be disposed on bottom wall 44. The indentation or protrusion
can
be of various shapes and sizes so long as nut 10 and insert 20 are
rotationally
coupled upon loosening.
Nut 50 (FIG. 4) includes a sidewall 52, a top face 51 and a bottom face 58.
Top face 51 includes a recess 56. The recess 56 includes a bottom wall 54 and
a
sidewall 55. Nut 50 also includes an orifice 53 therethrough. The orifice 53
is
preferably threaded. Sidewall 55 also includes at least one protrusion 57. As
described above an insert can be placed in recess 56 and nut 50 tightened.
Upon
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tightening, a portion of cylindrical portion 21 of insert 20 (FIG.2) will be
forced
against protrusion 57 and deformed into mating engagement. This engagement of
insert 20 and nut 50 provides for a rotational coupling of the nut and the
insert,
thereby preventing or at least greatly reducing the incidence of insert and
nut
separation. In alternative embodiments, in place of protrusion 57, at least
one
indentation can be disposed on sidewall 55. The indentation or protrusion, can
be
of various shapes and sizes so long as nut 50 and insert 20 are rotationally
coupled
upon loosening.
FIGS. 5 and 6 illustrate yet another embodiment of the present invention. Nut
80 has a top face 82, an orifice 84 and preferably a recess 87. Top face 82
includes
preformed indentations 85a and 85b. Insert 90 includes a portion 92 extrudable
across top face 82 of nut 80, and a cylindrical portion 91. Cylindrical
portion 91
includes preformed nut-engaging protrusions 93a and 93b. Preferably nut-
engaging
protrusions 93a and 93b are completely complementary to indentations 85a and
85b.
However, protrusions 93a and 93b and indentations 85a and 85b can be less than
completely complementary, so long as some rotational coupling is accomplished.
Upon insertion of insert 90 into recess 87 of nut 80 and in particular
insertion of
protrusions 93a and 93b into indentations 85a and 85b, nut 80 and insert 90
are
rotationally coupled. It is to be understood that the opposite arrangement of
a
preformed complementary protrusion and indentation can be used. Namely, a
preformed protrusion on the nut and a preformed nut-engaging indentation on
the
insert. Also, combinations of a preformed protrusion and a preformed
indentation can
be used on a nut or an insert. Additionally, the preformed protrusion or
preformed
indentation can be formed on an undersurface of portion 92 or on a sidewall or
a
bottom wall of recess 87 or combinations thereof.
FIGS. 7 and 8 illustrate still another embodiment of the present invention.
Nut
60 has a top face 61 and a recess 62 having a sidewall 64. Recess 62 contains
a
peak 63. The presence of peak 63 at least partially disrupts the symmetry of
the
perimeter of recess 62. The perimeter of recess 62 includes at least a portion
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extending down sidewall 64. The perimeter of recess 62 is not completely
symmetrical because if a representation of recess 62 was folded across line A-
A, peak
63 would not correspond to the portion of recess 62 it was folded onto.
However,
if a representation of recess 62 was folded across line B-B the left and right
sides
would correspond. Insert 70 includes a portion 72 extrudable across top face
61 of
nut 60 and can include a cylindrical portion 71. Cylindrical portion 71
includes a peak
73. Insert 70 is fittable in recess 62 so that peak 73 engages peak 63 thereby
rotationally coupling insert 70 and nut 60. It is to be understood that other
partially
or completely asymmetrical configurations are within the scope of the present
invention. Portion 72 has a perimeter 74 which can be congruent with the
perimeter
of portion 71 or which can be circular or otherwise shaped.
Alternatively, recess 62 can have a perimeter which includes at least one
corner. Typically such a corner will be provided by having recess 62 formed in
the
shape of a regular polygon. Such polygons include triangular, square,
rectangular,
pentagonal, hexagonal etc. Insert 20 (FIG. 2) would then preferably have a
corresponding perimeter, although, any combination of recess and insert shape
which
allows for insertion of the insert into the recess and provides rotational
coupling can
be used.
FIGS. 9 and 10 illustrate another embodiment of the present invention. Nut
100 has a top face 101 and an orifice 102. Recess 107 includes bottom wall 104
and sidewall 103. Nut 100 also includes a second orifice 105 which preferably
is
disposed through sidewall 103 of recess 107 as depicted in cross-section in
FIG. 10.
Insert 20 (FIG. 2) can be fitted into recess 107 and pin 106 can be inserted
through
orifice 105 and into the cylindrical portion 21 of insert 20, thereby
rotationally
coupling the insert and the nut.
FIGS. 11 and 12 illustrate still another embodiment of the present invention.
Nut 1 10, shown in cross-section includes a threaded orifice 112 and a recess
113
having a bottom wall 114. Recess 113 also includes circumferential groove 115
thereabout. Insert 120 which includes deformable lip 121, cylindrical portion
122
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and lower lip 123 is shown in FIG. 12 and in place in FIG. 1 1. Lower lip 123
engages
in a snap-lock fashion groove 1 15 in nut 1 10.
FIG. 13 illustrates nut 130 which includes top face 131, outer sidewall 132,
threaded orifice 133 and recess 134. Recess 134 includes bottom wall 136 and
sidewall 135. Adhesive 138 can be applied to recess 134 or adhesive 137 can be
applied to threaded orifice 133. The adhesive could also be applied to the
insert
rather than the nut. In this regard, for purposes of this invention, the
thread area is
intended to mean not only those surfaces that are threaded, but also those
that are
functionally although not necessarily physically threaded such as friction
coatings.
A pliable friction coating that simply interferes with thread clearance would
have
beneficial effects similar to an adhesive coating.
The presently disclosed embodiments are therefore to be considered in all
respects as illustrative and not restrictive, the scope of the invention being
indicated
by the appended claims, rather than the foregoing description, and all changes
which
come within the meaning and range of equivalency of the claims are therefore
intended to be embraced therein.
